这一信道模型能够描述由电离层和对流层反射的短波信道，以及建筑物密集的城市环境。12瑞利衰落只适用于从发射机到接收机不存在直射信号（LoS，Line of Sight）的情况，否则应使用莱斯衰落信道作为信道模型-This channel model is able to describe the HF channel reflected by the ionosphere and troposphere, as well as building a dense urban environment.

使用哈夫曼编码的方法对文本进行压缩。可以是加密压缩，也可以是无密压缩(Huffman coding is used to compress the text. It can be encrypted compression or non dense compression)